Indian authorities have been urged to investigate the killing of a prominent journalist in Indian-controlled Kashmir.

Politicians, rebel groups and separatist leaders have condemned the murder of leading editor Shujaat Bukhari.

Indian authorities must ensure a “thorough and credible” probe into the shooting death and bring the killers to justice, the Committee to Protect Journalists (CPJ) said.

The media watchdog, however, questioned whether the government would conduct an adequate probe.

“Given the number of unsolved journalist murders and the political turmoil in Kashmir, we are concerned whether the Indian authorities will investigate this murder in a timely and effective manner,” CPJ deputy executive director Robert Mahoney said in a statement.

Relatives of Shujaat Bukhari (Dar Yasin/AP)

“Until justice has been served, the killing of Shujaat Bukhari will exacerbate the climate of fear in which journalists work in the state.”

The journalist was killed along with his two police guards by unidentified gunmen on Thursday evening as he left his office in Srinagar, the disputed region’s main city.

Mr Bukhari, in his early fifties, was a group editor for three daily newspapers and a weekly, including the English-language daily Rising Kashmir.

He is survived by his wife, son, daughter and parents.

Thousands participated in Mr Bukhari’s burial.

Kashmiri men at the funeral of Shujaat Bukhari in Kreeri, 25 miles from Srinagar (Dar Yasin/AP)

The killing was condemned by Indian home minister Rajnath Singh, opposition leader Rahul Gandhi and pro-India politicians in Kashmir, who called it “cowardice and a mindless act”.

Separatists and armed rebels who challenge India’s sovereignty over Kashmir also condemned the killing and demanded an independent probe.

Police said the assailants came on a motorbike and fired a volley of bullets towards the victims, leaving Mr Bukhari and his guards in a pool of blood.

No motive has been determined for the killing, but police accused rebels fighting against Indian rule.

Top rebel leader Syed Salahuddin, who heads the United Jihad Council, an umbrella group of 13 Kashmiri rebel organisations, called for an international investigation.

“The killing of Shujaat Bukhari at a time when the UN Human Rights Commission released a report on the human rights abuses by Indian forces in Kashmir raises many questions,” the newspaper Greater Kashmir quoted Salahuddin as saying in a statement.

Salahuddin said they have a “firm belief that Indian agencies and their agents were behind the murder of Bukhari”.

Mr Bukhari was an advocate for a peaceful resolution of the Kashmir dispute and was often part of peace conferences between India and Pakistan attended by former diplomats and generals from both countries.

Kashmiri men carry the coffin of Shujaat Bukhari (Dar Yasin/AP)

Journalists in Kashmir have worked under tremendous stress and have been targeted in the past, some fatally, by both the Indian state and militant groups.

The CPJ said at least six journalists have been murdered “with complete impunity in direct retaliation for their work in the state since 1992”.

Many media groups condemned the killing.

The Editors Guild of India said the “dastardly attack” on Mr Bukhari was a “new low”.

The Foreign Correspondents’ Club of South Asia in New Delhi demanded an immediate probe and appealed to authorities to find the attackers and punish them.

Kashmir is divided between India and Pakistan, but both claim it in its entirety.

Rebels have been fighting Indian rule since 1989, demanding that the territory be united either under Pakistani rule or as an independent country.

India accuses Pakistan of arming and training the rebels, a charge Pakistan denies.

Most Kashmiris support the rebel cause while also participating in civilian street protests against Indian control.

Nearly 70,000 people have been killed in the uprising and the ensuing Indian military crackdown.